Process of making printing-plates.



NLA. DROITGOUR.

PROCESS 0F MAKING PRINTING PLATES.

` APPLIOATION FILED JUNE 27, 1907. K 91 2,092, l Patented Feb. 9, 1909.

3 SHEETS-SHEET 1.

I wlTNEssEs. I 2a I MEN-r 0%. Ww. M/wcl mam@ M. A. DROITGOUR. PROGBSS 0F MAKING PRINTING PLATBS.

APPLICATION I-ILED JUNE 27, 1907.

Patented Feb.'9, 1909.

.s SHEETS-SHEET 2.

` I mvEN-ron. .5 WML/e @MM A M. A. DROITGOUR. PROCESS 0I MAKING PRINTING PLATES.

APPLIOATION FILED JUNE 27, 1907.

Patented Feb. 9, 1909.

3 SHEETS-SHEET 3.

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FIG. 9

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WITNESSES.

`the grinding of the back MICHAEL A. naoi'rcoUR, oF PITTSBURG, PENNSYLVANIA.

Pnocsss oF MAKING PRINTING-PLATES.

Specification of Letters Patent.'

Patented Feb. 9, i909.

Application led June 27, 1907. Serial No. 381,067.

To all whom 'it may conc-ern.:

Bc it known that I, MICHAEL A. DROIT- CoUn, resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Im rovement in Processes of Making Printin-A lates; and I do hereby declare the following to be a full, clear, and exact description thereof.

This invention relates to a method of maki ing printing lates of plastic material, and

more especia y to a method of making such plates from celluloid or other material which can be softened by heat.

The object of the invention is to provide a method of making such plates whereby the cost of producing -printing plates is greatly reduced over recesses now in vogue and also whereby t e ex ensive process of building up the plate, as 1s done for fine book and magazine work, is dispensed with In the printing art there are two .processes in use, among others, of making printing plates, one the electro-plate process and the other the stereotype process. In both of these processes the plates are made from metal and the processes are slow and expensive and especially so 'for fine work Where it .is

' found necessar to build up the lates due to the impossibility of getting uniform thickness of plate in order to secure a uniform impression over the entire age.

My rocess is intende to take the place of the or inary electro-plate or stereotype processes and its object is to greatly simp ify, expedite and cheapen the process of makingthe printing lates, and especially to dis ense with the s ow and expensive work of bui ding up the plates for fine work.

Generally stated, the process consists in .i formin such printin plates from celluloid orother p astio materia which is capable of beine' softenedfor molding to the matrix and will then haiden to maintain this form.

In the preferred practice the process consists in the a plication of steam directly to a face of the p astic sheet laid against the ma-l trix in order to both soften the sheet and also press it into the depressions in the matrix.

The invention also comprises other process steps, such as the coolinfr of theplastic sheet,

thereof to` get uniform thickness, and for some purposes, the owing of some suitable plastic material onto thelback of the sheet to thicken. and

55. strengthen lthe same.

a front view of a suitable press ada ted for formin the plastic printing plate; F1 2 is a vcrtica section through the same s owing the parts preparatory to pressing; Fig. 3 is an end view of the press; Fig. 4 1s a vertical.

section `showin r the application of the cellu. loid backing; Fig. 4 is a sectional detail showing a different position of the valve Fig. 5 is aperspective view of the frame used; Fig. 6 is a sectional view of the same; Fig. 7 is a section on an enlarged scale through the matrix, the plastic sheet and frame laid on the same showing the same before the application of the steam; Fig. 8 is a similar view showing these parts after the application of the steam; Fig. 9 is asimilar view after the application of the plastic backing material; his. 10 is a diagrammatic view illustratin tie grinding ofthe back of' the plate; and ig'. 1lA ,is a vertical sectional -View' through a press showing afmodified method. In carrying out my proce'ssany suitable plastic material capable of being softened for molding and'afterwards set may be used, but I prefer to use celluloid or sinnlar pyroxylin composition, although if desired hard rubber can take its place. Also I prefer to use steam as the medium for heating the plastic. sheet and pressin it down into the matrix but an other suita le Huid medium capable of'so l tening the composition and of exerting pressure against the same will answer the `purose.

p For vbrevity in the detailed description herein I shall refer to celluloid as com osing the plastic material and to steam as t e mediumpfor softening the same and pressing, it

into'the matrix but' I wish it distinctly un' for the pu ose. I startJ Wit a matrix 1 "Which'may' jeformedI in any desiredl Way suches'from paperpulp, sheets of meistens paperyor in fact I may, use .any of .the'known methods for forming' such matrices from' the.

type form or other matter tov be` reproduced.

.to 4 have shown one form of ress suitable ilo and then place a frame 3 u on this sheet,- said frame resting u on the e ges thereof, as

shown in Fig. 7. 'I ese assembled parts are then placed 1n the press which, as shown, comprises a bottom platen 4 and a to platen 5 which can be brought tightly toget er and again-separated by suitable means, such as screws 6 rovided with gears 7 meshing with a` centra gear provided with a handle 8 whereby said screws can be rotated in unison. rlhe matrix, celluloid sheet and frame 3 are tightl clamped between the platens of the press, t 1e platens of the press bein preferably heated, such as by being made ollow and providing one thereof with a steam inlet 9 and connecting the chambers of the two platens by means of a tube or flexible pipe 10. Steam is then admitted between t e top platen 5 and the top or back face of the ce lu oid sheet 2, such as by admitting it from the chamber in thetop platen through an opening 11which is controlled by a suitable valve 12. 'lhe steam introduced between the top platen and the celluloid sheet is confined by the frame 3 on the edges of said sheet. 'l he steam acts in a two-fold caacity, first, by its heat to soften the celluoid, and second, b its pressure to press the softened `celluloid own into the depressions in the matrix. The consequence is that the lower face of the celluloid sheet is given a form which is an exact reverse of the matrix. Fig. 8 shows the celluloid sheet pressed into the matrix. Obviously any fluid medium which would act to soften the sheet 3 and to down into ver act by pressure to press it down into the matrix would serve equally as Well as steam, for instance, a heated gas under pressure.

Where time is not an essential element, and especially for fine screen work, half tone engravings, etc., the celluloid sheet 3 will be very thin, say one one-hundredth or two onehundredths of an inch in thickness, so as to require only a few seconds for softening and pressing down into they matrix, and will press ine lines in the matrix. When such a t in sheet is used it must be backed to give it sufficient body to resist the pressure oi the printing press. I back the same by flowing onto the same while still in the press some plastic material which will forni a close adhesion with the sheet. Many forms of plastic material can be used for this urpose, one of them being celluloid which will Weld to the thin sheet in the matrix and form practically an'integral portion thereof. The celluloid 1n a softened or semi-liquid condition is contained in a suitable reservoir 14 from which leads a pipe which spreads out, as indicated by the dotted lines 15, Fig. 1, into a wide nozzle 15 communicating with the space belowthe laten 5 and within the framenBugTheMcellu oid is forced into this space by any suitable means, such as steam pressure applied on top of the celluloid in reservoir 14, as through pipe 16, or by a mechanical plunger acting in said reservoir to force the celluloid into the press. The reservoir 14, nozzle 15 and other parts are inclosed in a steam jacket 17 to keepy the celluloid-in conditionto flow. The 'nozzle 15 is provided with valve 18 havin a passage` 19 through which the celluloi flows. The frame 3 has one side reduced, as at 20, to the width of the nozzle 15, to ermit the celluloid to enter the space above t e sheet 2, in a thin wide stream. When this is accomplished the source of the celluloid is cut off and the plate so formed is cooled, such as, for instance, turning offv the steam from the platens 4.and 5 and admitting water into.

said platens which may be done through a pipe 22. This cools the plate rapidly, causing the celluloid to set. To overcome the effect of shrinkage in cooling and to give a perfect type reproduction, the celluloid is ield under pressure while coolino. This is accomplished by providing the vz Ive 18 with a groove 23, so positioned that when the molten celluloid is cut oil', as shown in Fig. 4", said groove connects a steam pipe 24 with the space back of the celluloid in the press, and this holds the celluloid under pressure while coolin and prevents shrinkage. On the front of le frame 3 is a groove 25 communicating with a vent 26 in the lower platen, said vent being controlled by a valve 27 by means of which it can be determined when the space in the press is entirely filled with celluloid. When the celluloid is cooled the ress is opened and the celluloid sheet can Ihe readily removed from the matrix, after which the matrix can, if necessary, be used in making other similar plates. The Water and steam in the platens are drained out through the cock 28. A pressure valve 29 is also provided to retain the necessary steam pressure. The `plate so `rorhiccd is liable not to be uniform in thic ness at all points and in printing would give dil'erent degrees of impression on different parts of the plate. To overcome this and produce uniformity of impression I remove from the y as a cylinder 3() and the back thereof is subjected to the action of any suitable instrument, such as a grinding Wheel 31. The plate, when curved onto the cylinder contacts with the cylinder on all of its type oints and conse uently when ground down 1s of uniform thic ness between its back and' all of its type points, thus insuring uniformity of impresslon While printin.n

In the process of mol g, the matrix ISLz forms a thin margin on ,the sheet, as shown at 33, which serves as a means of attachmentl to the press cylinder or pressplaten and revents printing on the margins. The ate is then trimmed in any suitable Way andl the edge portions 33 may be punched with holes for attachment to the cylinder of a ress. For work not requiring such fine ines, such as for ordinary newspa er Work and in which s eed in making the p ate is especially ldesirab e, the Celluloid sheet may be some'- What thicker, such as say from threethirty-seconds to one-sixteenth of an inch. This requires slightly more time to soften the same butidoes not require a backing. In this case I prefer to proceed as shown in Fig. 11, the parts being put in the press upside down with the matrix against' the top platen and the Celluloid sheet 35 below the same. Steam in this case is admitted from the bottom and serves to soften and press the Celluloid into the matrix as heretofore described. To hasten the rocess the .sheet may be heated rior to p acing it in the press, which may e done 1n a suitable oven or steam chamber. After pressing, the Celluloid plate may be cooled in the manner above described but preferably b admitting water directly in- Contact Wit the lower face of the Celluloid plate. This is why I place the ,parts in the press upside down so that the water cannot come in Contact with the matrix, as it would cause the latter to swell. After cooling the high spots on the back of the plate are removed in the manner described in connection with Fig. 10.

My method of making plates is very expeditious, as it has been found' that an application of steam for a period of five seconds suffices to soften the Celluloid and press it fully into the matrix. The backingl of the sheet when necessary and the cooling are very quickly performed and the subse-l v gives equally as good results in fine magazine and book work as with stereotype or electro type plates in which several days time of an expert has been, consumed in building up to pro er thickness. The Celluloid presses down into the matrix with such exactness that it has been found possible to reproduce half tone Work in fine screens.

What I claim is:

l. The method of making printing plates, consisting in forming a matrix, laying on the same a sheet of plastic composition, then applying to the back of said sheet hot uid under pressure to soften the sheet and simultaneously press the same into the matrix, and then cooling said sheet.A

2. The method of making printing plates, consisting in forming a matrix, layin on the same a sheet of plastic composition, t en applying steam to the back of the sheet to soften the same and simultaneously press it into the matrix, and then cooling said,-

3. ,The method of making printing plates',- consisting in forming a matrix, layihg on the same a sheet of proxylin composition, and then applying to t e back of said sheet a hot fluid under pressure to soften the sheet and simultaneously press it into the matrix.

4. The method of making printing plates, consisting in forming a matrix, laying on the same a sheet of pyroxylin composition, and then applying steam to the back of said sheet to soften the same and simultaneously press the same into the matrix.

5. The method of making printing plates, consisting in forming a matrix, laying on the same a. sheet ofv plastic composition, then applying to the back of said sheet a hot fluid under pressure to soften the sheet and simultaneously press the same into the matrix, and thereafter applying a cooling medium to harden the sheet.

6. The method of making printing plates, consistinor in forming a matrix, laying on the same a s ieet of lastic composition, applying to the back o said sheet a hot iuid under pressure to soften the sheet and press the same into the matrix, and holding the same under pressure while cooling.

7. The method of making printing plates, consisting in forming a matrix, pressing into the matrix a sheet of plastic composition b applying fluid'pressure directly to. the back of said sheet, and applying fluid pressure directl to the back of the printing plate so forme to set the same.

8. The method of making printing plates, consisting in forming a matrix, pressing into the matrix a layer of plastic com osition, then flowing onto the back of sai layer a plastic backing material, and holding the same under pressure While setting.

9. The method of making printing plates,

consisting in forming a matrix, laying on the same a sheet of plastic composition, then applying to the back of said sheet a hot fluidv under pressure to soften the same and simultaneously press the same into the matrix,

and then flowing onto the back of said sheet a plastic backing material.

10. The method of making printing plates,

1 1. The method of making printing plates, consistin in forming a matrix, layi on the samea s eet of pyroxylin composition, applying to the back of said sheet fluid under pressure to soften the same and simultaneously press the same into the matrix, and then flowing onto the back of said sheet a plastic pyroxylin backing composition.

12. The method of making printing plates, consisting in forming a matrix, laying on the same a sheet of plastic composition, a plying to the back of said sheet a vhot ilui under pressure to soften the sheet and press it into the matrix, and then removing the surplus material from the back of said sheet.

13. The method of making printing plates, consistin in forming a matrix, laying on the same a s eet of lastic composition, apply ing to the back o said sheet a hot fluid under pressure, and when said sheet has set removing the same from the matrix and placing the same type-face against an accurately formed surface, and then removing the surplus material from the back of said plate.

14. The method of making printing plates, consistin in forming a matrix, laying on the same a s eet of lastic composition, apply ing to the back ofp said sheet a hot fluid under pressure, `a plying to the back of said sheet a layer of p astic material, placing said shee't typle-face against an accurately formed cy nder, and then removin the surplus material from the back of sai plate.

15. The method of making printing plates, consisting in forming a matrix, pressing into the same a sheet of plastic composition, ap-

plying to the back of said sheet a layer of plastic backing material, placing said sheet type-face against the surface of an accurately formed cylinder, and then subjecting the back of said sheet while' so held to the action of a tool constructed to remove material from said sheet.

16. The method of making printing plates, consisting in formin a matrix, laying on the same a sheet of p astio composition, applying to the back of said sheet a hot fluid under pressure, and when said sheet has set removing the same from the matrix and placing the same type-face a ainst the surface of an accurately formed cy `nder,' and subjecting the back of said sheet to the action of a tool constructed to remove material from said sheet.

In testimony whereof, I the said MICHAEL A. DROITooUR have hereunto set my hand.

, M. A. DROITCOUR. Witnesses:

F. W. WINTER, ROBERT C. To'r'rEN. 

